In psychology, narcosynthesis refers to a group of techniques which has its origins in the practice of "narco-hypnosis." Narco-hypnosis, as its name implies, is the use of various narcotics to induce various types of hypnotic states. In conjunction with traditional hypnosis techniques, it was thought that the desired psychological effects might be facilitated faster or with more "psychic depth" than hypnosis alone. If hypnosis remains a mysterious science, then narcosynthesis and narcohypnosis are all the more mysterious simply because of misunderstanding and ideas popularized by films such as Conspiracy Theory where the main character is pursued by the "mad scientist" type whom, in the instance of this film, is asscociated with the CIA (although it is common in cinema to find these characters associated with any number of governmental intelligence agencies).

Narcosynthesis is thought to have had a military origin where therapists worked with soldiers to recall battle traumas, and subsequently attempt to treat or reduce the effects of "shell shock" and other manifestations of psychological trauma associated with battle. By augmenting standard hypnosis with narcotics and "synthesizing" mental states through the power of hypnotic suggestion, a negative mental state could be sublimated by a positive one.

A highly simplified example of this would be in the case of a returning veteran experiencing extreme anxiety or panic at a backyard Fourth of July celebration simply because someone had lit a pack of firecrackers. A trained medical professional may employ narcosynthesis to induce a pleasant memory of an earlier Fourth of July experience and then strongly suggest that the sound of the firecrackers could once again be associated in the mind of the patient with the pleasant memory rather than the traumatic one.

The efficacy of such techniques remains a source of debate among medical professionals. It is however the ethical aspects of this area of psychology which provide the greatest challenge to society, as the malleabilty of the human psyche is well documented throughout history.